Distractors
Its line of pull relative to the mediolateral sagittal-plane axis of motion for the lumbar spine doesn’t change with postural change of the spine
Because it is a spinal flexor, it cannot create increased lumbar extension
When the sacral-base angle increases to 45 degrees, a greater percentage of psoas major fibers cross the spine anteriorly
Key
Even though it is a spinal flexor, it can result in increased lumbar extension
Question
In “Cool Muscles,” author Joe Muscolino says one paradox of psoas major function is: